[Rolex.c6]

Okay, this may be a stupid question but why is it every time a serial number of a watch is in a picture it gets blurred?
Why is everybody keeping the serial numbers of their watches a secret? Can another person abuse this information if they have it? I really tried to think of the answer myself but couldn't come up with anything that could cause a threat if you share it.
But being relatively new to this all I'm probably overseeing something...